Two engaging curvic couplings may be used to rotationally couple two elements, such as rotation shafts, connected to the respective curvic couplings. The curvic coupling may also be referred to as a clutch member or clutch wheel. In particular, the curvic coupling may be referred to as a toothed face clutch.
GB 592,648 discloses a toothed face clutch and a method for producing the same, wherein the clutch member comprises teeth, which have longitudinally craft helical side surfaces.
GB 572,612 discloses a face clutch and a method for producing the same, wherein two surfaces are longitudinally convex or longitudinally concave.
GB 1,439,707 discloses a coupling device having means for relieving circumferential stresses, wherein one coupling member has lug elements with concave sidewall configurations, whereas another coupling member has lug elements with sidewalls which are convex.
The coupling element or curvic coupling which has teeth having curve side surfaces may also be referred to as curvic coupling wheel or curvic coupling element. Conventionally, a curvic coupling is produced with a gable angle at the base of the profile (trough) to ensure that there is a consistent tooth form produced without mutilation of the teeth or a fin condition observed. Iteration of the designed parameters may be used to modify the design until a suitable profile has been attained.
A coupling element or curvic coupling may be manufactured by grinding using a grinding tool, such as a circular grinding tool having a cross-sectional shape (also refer to as grinding profile), which is suitable for cutting out material from a raw circular working piece in order to produce the curvic coupling. Thereby, the grinding tool or cutter is rotated and is lowered to a raw working piece in an axial direction. Thereby, the grinding tool or cutting tool may at the same time grind or machine two side surfaces of two teeth which are spaced apart in the to be manufactured curvic coupling. When one trough between two adjacent teeth or in particular when two troughs (in particular recesses) between two pairs of respective adjacent teeth have been grinded, the cutting tool or grinding tool is lifted to be withdrawn from the working piece. The working piece is then rotated around its rotation axis to reach another rotational position, at which the grinding tool is again lowered to grind or machine two other troughs between two other pairs or adjacent teeth.
It has been observed that a coupling element may not be inspected or monitored regarding accuracy of the geometry of the coupling element without having readily access to a calibrated set of inspection masters. Typically there are only a low number of sets available for each coupling geometry e. g. one set that is retained by a tool supplier e.g. Gleason Works for reference and one set with the OEM for calibration of the coupling production.
There may be a need for a curvic coupling for rotational coupling, for a coupling system comprising two such curvic couplings and for a grinding tool for manufacturing the curvic coupling.